Something's wrong with the GPU process. It has switched to the Software Webrender, so it's crawling.

Try to enter about:support in the address bar and find the GPU process line in the Graphics section.

I did as you said. GPU process says: GPU_PROCESS default available runtime failed Failed to connect GPU process

Try to start Firefox in Troubleshoot Mode to see if that works.

• Windows: hold down the Shift key while starting Firefox
• Mac: hold down the Options key while starting Firefox

• https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode

You can create a new profile as a quick test to see if your current profile is causing the problem.

See "Creating a profile":

• https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles

If the new profile works, you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

Boot the computer in Windows Safe Mode with network support to see if that has effect.

• https://www.bleepingcomputer.com/tuto.../how-to-start-windows-in-safe-mode/
• https://www.digitalcitizen.life/4-ways-boot-safe-mode-windows-10/

cor-el, I started Firefox in troubleshoot mode as you suggested and was able to use the browser without difficulty at first as soon as I disabled hardware acceleration. It seemed to work great, but when I logged off of my desktop and later logged in, the problem was back again. Then when I tried to start in troubleshoot mode on my grandchildren's desktop, Firefox didn't work at all. It would come up but the spinning icon that says it's still loading continued to spin...as it did on my desktop...again.